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Introduction

• What is an oscilloscope?

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Introduction

A graph-displaying device of electrical signal X axis: Time Y axis: Voltage Z axis: Intensity or brightness

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Introduction

Information given by oscilloscopes Time and voltage Frequency and phase DC and AC components Spectral analysis Rise and fall time Mathematical analysis

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Control panel of an oscilloscope

Vertical Section Horizontal Section Trigger Section

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Basic setting

Vertical system attenuation or amplification of signal (volts/div)

Horizontal system The Time base (sec/div)

Trigger system To stabilize a repeating signal and to trigger on a single

event

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Analog oscilloscope

Real-time display of signals Block diagram

Sweep generator and vertical amplifier Earthquake recorder

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Digital oscilloscope

Capture and view events Digital storage oscilloscope (DSO)

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Digital oscilloscope (contd.) Sampling

Interpolation

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Advantage of Digital Scope Trend towards digital. Easy to use. One-shot measurement Recoding Triggering Data reuse Connectivity

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Probes

Components

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Probes

High quality connector High impedance (10M)50 for high frequency measurement

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Passive probe

10 attenuation Good for low circuit loading Suitable to high frequency signal Difficult to measure less than 10mV

signals 1 attenuation

Good for small signals Introducing more interference

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Active probe

Signal conditioning oscilloscope⇒Require power sourceGood for high speed digital signals over

100MHz clock frequency